PPindex.class	find PPindex value
PPindex.LDA	calculate LDA index value
PPindex.Lp	calculate Lr index value
PPindex.PDA	calculate PDA index value
PP.optimize.ramdom	optimize with random search
PP.optimize.anneal	optimize with simulated annealing
PP.optimize.Huber	optimize with Huber's method	
PP.optimize.plot	make plot after optimizing
PP.tree			make PP tree structure
PP.classify		estimate classifier after fitting
